BRIDGEPORT -- Lyn Salsgiver was listening to the radio when she heard a news item that both pleased and confused her. A Gallup poll had named Bridgeport one of the least obese cities in the country.

"I said `Wow!' But it didn't make sense, given our data," said Salsgiver, a facilitator for the anti-obesity coalition Get Healthy CT and Bridgeport Hospital's vice president for strategy and business planning.

It turns out the news item was only partly true.

The Gallup poll named the collective Bridgeport-Stamford-Norwalk metro area -- a big chunk of real estate that encompasses most of Fairfield County -- as the ninth-fittest community in the United States, with an obesity rate of 19.6 percent.

That makes more sense, Salsgiver said, as that area includes such suburbs as Easton and Fairfield, which tend to have relatively low obesity rates.

In Bridgeport itself, the rates are much higher. A 2011 survey of about 1,700 Bridgeport residents showed that roughly 36 percent were considered obese, said Kristin duBay Horton, Bridgeport's director of health and social services. "When you group Fairfield County together, and that becomes `Greater Bridgeport' that creates a problem," she said.

To make the point, Salsgiver cited another study, the 2012 Community Health Needs Assessment, which surveyed residents of Bridgeport, Easton, Fairfield, Monroe, Trumbull and Stratford. In that poll, 32.6 percent of Bridgeport residents polled were considered obese, along with 27.5 percent of Stratford residents surveyed and 23.4 percent of Monroe and Trumbull residents. However, only 16 percent of Easton and Fairfield residents polled were considered obese.

"Fairfield County looks kind of rosy (as a whole), but when you look at certain areas, we have more challenges," said Stratford Health Director Andrea Boissevain.

She and other health leaders are looking to address barriers to fitness in their communities. For instance, duBay Horton said Bridgeport officials are trying to get more nutritious foods to residents living in food deserts -- communities without ready access to a supermarket or other purveyor of healthy foods. The Get Healthy CT website, gethealthyct.org, also has a "Get Local" section, where users can access a list of farmer's markets and other healthy options in their city.

Obesity is mainly determined by body-mass index, a measure of body fat based on height and weight. A BMI of 30 or higher is considered obese and a BMI of 25 to 29.9 is considered overweight. Obesity is a contributing factor to multiple chronic illnesses, including heart disease and diabetes.

The Gallup obesity poll has come out every year since 2008. This year's results show that the least obese community in the country is Boulder, Colo., where 12.4 percent of residents are obese. Huntington-Ashland -- a region spanning parts of West Virginia, Kentucky and Ohio -- was named the least-fit community, with 39.5 percent of its residents obese.